/* *{
    margin: 0;
    padding: 0;
} */
/* id选择器 */
#main{
    color: blue;
}
/* 类选择器 */
.news_title{
    color: red;
}
/* 元素选择器 */
h3{
    color: coral;
}
/* 属性选择器 */
[title] {
    font-size: 1.5em;
}
p[date-bind] {
    color: crimson;
}
p[title="abc"] {
    color: darkblue;
}
p[title~="cd"] {
    color: darkorchid;
}
p[title|="xzy"] {
    color: deepskyblue;
}
a[href][title] {
    color: gold;
    font-size: 3em;
}
/* 伪类与伪元素 */
p:hover {
    background-color: lightskyblue;
}
li:hover {
    background-color: magenta;
}
a {
    color: red;
}
a:link {
    color:red;
}
a:visited {
    color: purple;
}
a:hover {
    font-weight: bold;
}
a:active {
    color: chartreuse;
}
input:focus {
    background-color:#abc ;
}
pre:first-child {
    color: red;
}
li:first-child {
    color: red;
}
div p:first-line {
    color: red;
}
div p::first-letter {
    font-weight: bold;
    font-size: 200%;
}
div h1:before {
    content: "before:"
}
div h1::after {
    content: ":after"
}
/* 后代选择器 */
div span {
    color: blueviolet;
}
p > span {
    color: cornflowerblue;
}
pre+span {
    color: red;
}
pre ~ span.pro {
    color: skyblue;
}